Infinite loop in HTTP client and HTTP server connectivity plug-ins.

If the HTTP server connectivity plug-in was sent a request with a gzip or deflate content-encoding header set but the body not actually compressed, then the HTTP server would never send a response to the client. This would exhibit a “chain is slow” warning in the correlator log. The HTTP server connectivity plug-in now safely handles this scenario and responds with status code 400 (Bad Request).